msg_receive - Receive a message from a message queue
Вернуться к: Semaphore Функции
msg_receive
(PHP 4 >= 4.3.0, PHP 5, PHP 7)
msg_receive — Receive a message from a message queue
Описание
$queue
, int $desiredmsgtype
, int &$msgtype
, int $maxsize
, mixed &$message
[, bool $unserialize
= true
[, int $flags
= 0
[, int &$errorcode
]]] )
msg_receive() will receive the first message from the
specified queue
of the type specified by
desiredmsgtype
.
Список параметров
-
queue
-
-
desiredmsgtype
-
If
desiredmsgtype
is 0, the message from the front of the queue is returned. Ifdesiredmsgtype
is greater than 0, then the first message of that type is returned. Ifdesiredmsgtype
is less than 0, the first message on the queue with the lowest type less than or equal to the absolute value ofdesiredmsgtype
will be read. If no messages match the criteria, your script will wait until a suitable message arrives on the queue. You can prevent the script from blocking by specifyingMSG_IPC_NOWAIT
in theflags
parameter. -
msgtype
-
The type of the message that was received will be stored in this parameter.
-
maxsize
-
The maximum size of message to be accepted is specified by the
maxsize
; if the message in the queue is larger than this size the function will fail (unless you setflags
as described below). -
message
-
The received message will be stored in
message
, unless there were errors receiving the message. -
unserialize
-
If set to
TRUE
, the message is treated as though it was serialized using the same mechanism as the session module. The message will be unserialized and then returned to your script. This allows you to easily receive arrays or complex object structures from other PHP scripts, or if you are using the WDDX serializer, from any WDDX compatible source.If
unserialize
isFALSE
, the message will be returned as a binary-safe string. -
flags
-
The optional
flags
allows you to pass flags to the low-level msgrcv system call. It defaults to 0, but you may specify one or more of the following values (by adding or ORing them together).Flag values for msg_receive MSG_IPC_NOWAIT
If there are no messages of the desiredmsgtype
, return immediately and do not wait. The function will fail and return an integer value corresponding toMSG_ENOMSG
.MSG_EXCEPT
Using this flag in combination with a desiredmsgtype
greater than 0 will cause the function to receive the first message that is not equal todesiredmsgtype
.MSG_NOERROR
If the message is longer than maxsize
, setting this flag will truncate the message tomaxsize
and will not signal an error. -
errorcode
-
If the function fails, the optional
errorcode
will be set to the value of the system errno variable.
Возвращаемые значения
Возвращает TRUE
в случае успешного завершения или FALSE
в случае возникновения ошибки.
Upon successful completion the message queue data structure is updated as follows: msg_lrpid is set to the process-ID of the calling process, msg_qnum is decremented by 1 and msg_rtime is set to the current time.
Смотрите также
- msg_remove_queue() - Destroy a message queue
- msg_send() - Send a message to a message queue
- msg_stat_queue() - Returns information from the message queue data structure
- msg_set_queue() - Set information in the message queue data structure
Вернуться к: Semaphore Функции